STANDARD - Survey Instrument Antique Center!

220
No. 12.
8-iiich Transit for Triangulation.
As made by C. L,. Berger & Sons.
No. 1 2. The form of frame chosen for mounting the telescope is similar to that in the
cut, which permits the reversal of the telescope through the standards as well as over the
bearings. It is of improved design and somewhat resembles that shown on page 219. It is very
stiff and very steady in strong winds, and being of aluminum, very light.
The inverting telescope has a clear aj)erture of 1 \ inches, focal length of 13J inches, power
28 to 32 diameters, reversible clamp and tangent; six-inch vertical arc graduated to read to
30* by a double vernier between the legs of the standard frame, figures run from to about
45 each way. The horizontal axis of the telescope is provided with a 4^-inch striding level
resting at points of contact in wyes. The horizontal circle is 8 inches in diameter, single opposite
glass-covered verniers reading to 10", one row of figures to 360 clockwise, with
reading glasses. The radius of the three leveling screw-base is larger than usual, and as the
head of the tripod is proportionately larger, the instrument has great stability. It is provided
with a shifting center. The Yoke standard frame will be japanned or cloth finished, as we
deem it best. In this, as in all our instruments, the fine appearance and general character
depends principally on simplicity of design, coupled with fine workmanship, and a high state
of efficiency of every part. Other parts that cannot easily be finished and lacquered in the
usual but mostly antiquated manner, are therefore also treated in japan.
This is in line with good taste and modern thought and improvements, to enable us to unite
as many pieces as possible in one to secure great stability and steadiness under all conditions
in order to arrive at quick and thoroughly reliable results. Made to order only.
Weight of instrument, 18 Ibs.; weight of tripod, 19 Ibs.
Price .as above, $4O5.OO
This instrument without arc and clamp to telescope, less $35.OO
No. 12a Transit with a six-inch full vertical circle (instead of with arc as shown in
cut) vernier frame all open as in style No. lib page 214, single opposite verniers
reading to 30", one row of figures to 360 clockwise, reading glasses, level to vernier
arm $443.OO
No. 12b Transit with a six-inch vertical circle with protected open-form vernier frame,
face-graduation, single opposite verniers glass-covered, as shown in cut page 219, reading
to 20", one row of figures to 360 clockwise, reading glasses, level to vernier arm,
$473.OO
Illumination of Cross Wires by Mirror,
Electric Bulb and Dry Battery.
This feature with the battery attached to a
to the
tripod leg is very convenient, but is open
objection that the small mirror* placed as it is in
the center of the telescope cuts out the best rays
of the object glass and at a point where al-
they
ready considerably converge toward the eye piece.
For this reason the simpler form of attaching a
reflector in front of the object glass is generally
preferred for the smaller transits.
Price, when ordered with Transit Theodolites
No. 12 to No. 15 . . . $22.OO
* The mirror can be removed ihen not needed for illuminating
purposes.